Subterranean service lines for gas and water normally utilize a curb box to provide access to the service line valve, and such curb boxes include a tubular casing having a lower bell housing for encompassing the service line valve. The upper end of the curb box includes a cover, and removal of the cover permits a wrench to be lowered into the curb box for actuating the valve operator head mounted upon the valve body. An example of a synthetic plastic curb box is shown in the assignee's U.S. Pat. No. 2,931,383.
The housing located at the lower end of the curb box is provided with an open end which is inserted over the service line valve, and the valve, and conduit, normally lie on the bottom of the trench receiving the conduit. It is now common practice to utilize synthetic plastic conduit as a service line for natural gas, and as such plastic conduit is transported and handled as a coil the laying of the conduit in a trench often results in the conduit tending to twist or otherwise misalign itself relative to the trench due to stresses in the conduit material produced during manufacture, or resulting from coiling. Accordingly, the difficulty in maintaining a given orientation of the conduit within the trench complicates the angular positioning of the valve on the synthetic plastic service line, and difficulty is often encountered in properly aligning, and maintaining, the valve within the curb box lower housing.
In order to improve the support of the valve with respect to the curb box it is known to utilize base structure mounted on the lower end of the curb box housing upon which the valve rests, and curb boxes having bases are illustrated in the assignee's U.S. Pat. Nos. 3,548,864 and 3,901,271. In a recent development of the assignee a base is employed with a curb box wherein a "snap-on" interconnection between the curb box bell housing and base occurs, the base being particularly suitable for use with conventional metal valves, and such structure is shown in the assignee's patent application Ser. No. 128,633 filed Mar. 10, 1980.
While the past common practice has been to use metal service line valves with sythetic plastic service lines, service valves have now been developed for use with synthetic plastic service lines which are, themselves, of a synthetic plastic construction, which improves the longevity of the valve, renders the valve compatible with the gas line, is light weight and provides excellent resistance to corrosion over long periods of service. However, such synthetic plastic valves are of such configuration, often cylindrical, which does not lend itself to accurate and firm positioning within the valve housing, or upon the base.
Additionally, many synthetic plastic valves presently available use either one of two types of valve operators which require a special valve operator configuration, necessitating that the service crew carry both kinds of valve operating wrenches in that the particular type of wrench required is not known until the curb box is opened.
It is an object of the invention to provide a curb box for subterranean utility service lines wherein the curb box firmly supports and positions a service line valve upon a base to which the curb box casing and valve housing are readily attached.
A further object of the invention is to provide a curb box construction having a removable base wherein a cylindrical valve may be firmly supported in a predetermined orientation within the curb box, and torsion forces exerted on the valve by the service line are effectively resisted by the curb box structure.
Another object of the invention is to provide a valve operator head for curb box usage wherein a single valve head accomodates either of the two most commonly used valve operating wrenches eliminating the necessity for a service crew to carry both types of wrenches, and further, the valve operator head is self-cleaning with respect to foreign matter falling thereupon which may interfere with wrench operation.
In the practice of the invention the curb box casing includes a lower valve receiving bell housing wherein opposite sides of the housing are slotted in order to define a pair of cantilevered spring portions in which a pair of vertically spaced base engaging abutments are defined. The removable base includes edges which engage the casing housing abutments, and the horizontal length of the base is substantially greater than the width of the valve housing whereby the base provides a high degree of resistance to rotation of the curb box assembly.
Further, the base includes a cylindrical cradle portion at its central region for closely receiving a cylindrical service line valve, and the lower region of the base includes an opening which receives a downwardly extending sprue or projection formed on the valve whereby the close relationship of the base and valve provides firm support of the valve relative to the curb box, and prevents the curb box from twisting or otherwise angularly disorienting itself with respect to the curb box, assuring proper valve actuator operation throughout the life of the service line.
The valve operator head includes a body of a generally square configuration having upper surfaces which are inclined to the horizontal to readily shed foreign matter falling upon the head. Further, an upwardly extending elongated projection diagonally oriented upon the head permits either a slot type wrench, or a square socket type wrench to be used with the head for valve actuation purposes. The self-cleaning aspect of the head assures full and complete engagement of the valve wrench upon the valve actuating head.